Mep 002a low power and low throttle response

[Tpoole]

The head has been completely rebuilt, compression is at 425, injectors are both new, fuel pop off at 1850psi the injection pump is timed correctly (I’m sure) the engine timing is correct as well; the governor is correct along with the governor spring and adjustment, throttle is adjusted good as well; I’m at a loss, good everything, 325 hours
Again engine hunts unloaded and doesn’t have much power, throttle response is very lethargic and very slow. I am a mechanic, i have been through all the manuals and everything is in spec
Has PSU pump with all new seals and a perfect delivery valve

 

[Ray70]

Ok, I went back and read your previous thread.
Regarding compression, if you have 425 in both cylinders that is fine. The manual says anything over 325 is good.
With the fuel pumps running do you hear fuel dribbling inside the tank through the return line?

Remove the top cover and start it up. Put a finger on both exhaust ports and see if the warm up in sync. with each other.
This will tell you if both cylinders are firing somewhat evenly.

With regards to the hunting condition, after performing the governor adjust procedure were you able to stop the hunting, or does it hunt no matter where the star wheel is set? How far up from the bottom is the spring now, should be about 3 turns up from the bottom.

If possible, get a video of the engine running and get a good video and some good pictures of the throttle arm on the IP as well as the governor arm with the side cover open. I also need a picture straight on looking at the tip of the governor arm where the vertical linkage attaches with the machine off. I want to compare the tip of the governor arm to the top of the fuel stop solenoid, if you can get a picture straight across, level.

Also get a picture looking straight down ( as best you can ) of the pivot arm that the throttle cable and governor spring attaches to.
The slightest bend in the Governor arm, slightest discrepancy with the Governor spring or binding throttle linkage can cause these issues.
Also check the linkage arm from the governor arm to the IP and make sure it expands when pulled out and sucks itself closed when the fuel stop solenoid is retracted and nothing is pulling it apart. Also make sure the ball cup on the IP end isn't cracked.

Lastly ( for now ) take a look at the max throttle stop screw that goes through the blower wheel cover and hits the pivoting throttle lever if you pull the throttle knob all the way out. At 60Hz 1800RPM, the pivoting arm should be about parallel with the end of the generator and it should not be touching the throttle stop screw.

 

[Tpoole]

 

[Tpoole]

I think I found our timing problem with the pump. look at the plunger and compare it with the picture in the manual, the manual states that the drive pin must line up with the distributor slot. if you look at the plunger the distributor slot and drive pin are i'm guessing about 20 degrees off. don't know how that could be because it looks like a solid piece, but i can't really tell.

 

[Ray70]

roll the plunger over 180 degrees and take another picture, I think you have the drive pin in the wrong side of the plunger, but I don't have an old PSU plunger here to compare with your pic., just going by memory.

 

[Ray70]

Actually never mind, I was looking at it wrong. You have it assembled correctly.

 

[Ray70]

It is one solid piece of hardened steel, so it will not have twisted or anything, but it does look odd, however I can't confirm they are supposed to be perfectly aligned without one to compare it with.
If you take out the drive pin does the round shank come straight out from the rectangular part?
The rod should be square to the rectangle, not angled at all.

 

[Tpoole]

It is one solid piece of hardened steel, so it will not have twisted or anything, but it does look odd, however I can't confirm they are supposed to be perfectly aligned without one to compare it with.
If you take out the drive pin does the round shank come straight out from the rectangular part?
The rod should be square to the rectangle, not angled at all.

Do you have anyone that maybe will sell one? I'm too deep into this thing to give up on it now! Thank you for your help

 

[Ray70]

I don't think you will find anyone selling a plunger, plus as mentioned, the plunger, body and metering block are a matched set and not intended to be interchanged.
Before going much further I think we need to confirm if you really have a problem with the plunger or not.
I do have a good PSU pump on the shelf, but would have to disassemble it to verify the plunger slot alignment, but really can't see any reason it would be damaged / twisted.
I think you have something else going on, but we don't really have all the detailed info regarding what you are seeing with the timing fluctuation etc.
Definitely don't give up, but we need more details.
Please check the email I sent last night regarding the timing button and please give us any additional info you can think of regarding what exactly you are seeing and what exactly you have done thus far.
I know you now have the machine apart, but a video would help immensely, as well as answers to the questions in post #2
Even the smallest detail may help us find the problem. For example, instead of simply saying the timing is correct, tell us how you checked the timing, did you use the pump flow method? And what did you find exactly. Were you dead on PC? 1 tick before, 2 ticks after??
What exactly did you mean by excess movement in the plunger?
All information is good information, so don't hold back!

 

[Light in the Dark]

Do you have anyone that maybe will sell one? I'm too deep into this thing to give up on it now! Thank you for your help

I think there are a number of unanswered questions in this thread already that would be beneficial towards narrowing the help.